This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an example described below, more particularly provides a drilling head with a non-rotating annular seal assembly.
A drilling head is typically used to seal off an annular space surrounding a drill string. Sealing off the annular space can be useful in certain types of drilling operations (such as, managed pressure drilling, including underbalanced drilling), in which a well annulus is pressure isolated from atmosphere at surface.
It will, therefore, be appreciated that improvements are continually needed in the arts of designing, constructing and utilizing drilling heads. Such improvements may be useful in managed pressure drilling operations, or in other well operations, whether or not the operations include drilling.